where \( \mathcal {L}_{heat} \)  is the 2D heatmap loss. \(\mathcal {L}_{loc}\)  and \(\mathcal {L}_{delta}\)  are location map loss and delta map loss respectively. \(\mathcal {L}_{reg}\)  is a \(\ell _2\)  weight regularizer to avoid overfitting. Please refer to Zhou et al.  [1]} for more training details.
